Pathological tolerance is a symptom that occurs in a stable triadic relationship with certain characteristics, including the sharing of a sexual partner. The term refers to inappropriate acceptance of the triangular relationship by the member of the primary dyad who is of the same sex as the "tradic addition." The author suggests that the intrapsychic and interpersonal dynamics of pathological tolerance are identical with those of pathological jealousy and include the reenactment of earlier conflictual relationships through symbolic representation, expression of homoerotic drives, and a variety of interpersonal patterns. He presents three case reports and recommendations for treatment.